High-Pitched Motor Noise

[victor_2019]

I'm not trying to silence people, I'm simply correcting wrong statements.

Lots of non technical people here are proposing solutions that simply make no sense from an engineering point of view, like fixing this noise by changing a gear.

One reason for this is lack of technical knowledge, but the more important reason is that people actually come here and talk about different issues and call all of them a "motor noise".

If someone comes here to complain about a motor whine, and it turns out that it was a bad bearing, or bad gear, or a failure in the rotor rubbing against stator, or countless other problems, then people will believe this will fix their harmonics noise problem, and if i say that has nothing to do with it, you'll complain that I'm trying to silence people?

The fact that some people can't hear this high frequency is not proof that their car doesn't make the noise.

Also i don't believe some cars start to make this noise later, as long as we're talking about the harmonics high frequency hiss, and not some other mechanical problem.

I didn't hear that noise in the beginning either, not because the car wasn't making it but simply because i wasn't looking for the noise.

Once i read about the noise and listened for it, i heard it. Even today i can't hear the noise unless I accelerate or regen with window open next to parked cars or large buildings. 99% of the time i don't accidentally hear this noise.
So most likely the people that didn't hear it before a certain point didn't have the precise circumstances required to hear it.

 

[MGrognon]

Thanks robxb and victor_2019

I think really all we are trying to figure out here is whether the hissing sound is on all Konas or not. I agree that some people are not talking about the same sound and also understand that most likely, the sound is to some extent a result of the (poor) design choices for the Kona's electric motor (or some other related components). However, I find it hard to believe that absolutely no one who's reviewed the car noticed this sound and that other than this forum and the Facebook group I'm on, no one has reported this (mind you there might be other forums or videos in other languages from other countries that discuss this ; who knows).

I agree that some people seem to confuse sounds here so let's try to sort this out. This is not the VESS clearly. If you think the problematic sound is this one in the video here, move along as this is not it :



The only other / different problematic sound people have complained about as far as I am aware of is a "rattle" of sort which is abnormal, and getting adressed/fixed by Hyundai from what I gather and is only present on a limited numbers of Konas and also some eNiros. Like this here (this is an eNiro though but some Kona owners have reported the same "rattle") :

.

This is not the "jet like" engine noise that most people find pleasant which you can clearly hear when you aggressively accelerate on the kona (example on video here around 2min43
).

We do hear that "hiss" a bit still even when you floor the Kona, but it's much more "blended in" and pleasant if that makes any sense when you put the pedal to the floor.

For most people on this thread, we are talking about the same hissing sound, present only when accelerating mildly to moderately or while using regen brake (not present at all when on neutral/coasting) and that was isolated on an MP3 earlier (specifically the Kona Noise SeanH.mp3 which is where you hear it the best). You can also hear it on the same video as above for the first time briefly @ 1min56 and more clearly around 2min29 or so but mixed with other motor and wind noises :

.

The sound is actually more present when you "gently" accelerate or regen than when you floor the Kona ; then the hissing sound is overall much more "blended in" and pleasant (if that makes any sense?) like a jet engine/turbine if you want (see 2min43 or so). The overall audio quality is poor, but I'd like to think most people in the thread are talking about the same thing and, as I said, are trying to figure out whether there is ANY way to get this fixed, or attenuated as much as possible.

And of note ; good for you victor_2019 that you don't hear it with windows up ; I do. I have to drive with A/C and/or radio full blast to not hear it which again makes me doubt that all Konas have the sound or have it to the same extent/volume at least ; I find it hard to believe I have some form of superman hearing or something. I know when my SO comes home as I can hear the Kona half a block away (and no ; I am not exagerating).

 

[victor_2019]

The only way you will get an answer to this question is to get in contact with the actual electrical engineers that designed the powertrain, they can tell what exactly in the switching patterns in the inverter is causing these frequencies and how they can be eliminated.

It's not the standard customer support people or even the local mechanical engineers that will be able to answer this.

 

[MGrognon]

The only way you will get an answer to this question is to get in contact with the actual electrical engineers that designed the powertrain, they can tell what exactly in the switching patterns in the inverter is causing these frequencies and how they can be eliminated.

Or why it is so damn loud on the Kona compared to other EVs on the market.

It's not the standard customer support people or even the local mechanical engineers that will be able to answer this.

I would tend to agree with you though, as the few people I spoke to at @ 2 local Hyundai dealerships' service department seemed genuinely clueless, one even told me this was the 2nd Kona (Electric) he ever saw other than those that came in for tire changes this past spring. Guess I'll have to learn Korean at some point.

 

[victor_2019]

Or why it is so damn loud on the Kona compared to other EVs on the market.

I really think it's mainly a question of volume.

I tested this again this morning with my honda clarity, and I can hear the same type of metallic hiss on the clarity. in fact on the clarity it sounds a lot more like metal scraping than on the kona (the sound "quality" is worse).

but it's much fainter than on the kona, probably a third in volume. (although in the kona it also gets less loud when I set regen level to 1 instead of 3, and the clarity regen is very weak, close to the kona level 1 at the clarity's maximum regen level. the kona really has extremely high regen capability compared to some other cars)

the answer to this might be very simple: the kona EV is based on a cheap car and the body is not as refined as other cars. The sound insulation on the kona is quite minimal, it's possible that more expensive cars like the teslas or from bigger companies like toyota/honda simply have better sound insulation/vibration deadening.

or we are simply unlucky and the motor vibrations are exciting some mechanical natural frequency in the kona's body, amplifying the noise. if that's the case, cars with the same powertrain like the niro or soul would not have the same problem because the car's body is different. even minor changes in the body, like the length, shape or thickness of certain parts will change the resonant frequencies of the body and might push the natural frequency outside the audible range.

 

[PNTABryan]

An issue for me is resale value. In 5 years, someone looking for a Kona will be looking for either a 2019 that doesn't make that noise or (hypothetically) a 2020 where they fixed the issue. MA lemon laws protect against this, I just thought Hyundai would be more open to figuring out a solution.

 

[victor_2019]

you're assuming that
1 - hyundai will fix the issue and

2- this issue is widely known outside of these forums. I have a hard time finding other resources where people discuss this issue

 

[PNTABryan]

you're assuming that
1 - hyundai will fix the issue and

2- this issue is widely known outside of these forums. I have a hard time finding other resources where people discuss this issue

Yep I hoped Hyundai would try to make sure customers are happy with their $40000 car, something Chevy showed when I bought a used car for $15000. If not I'll make sure nobody I know buys a Hyundai. Their loss in the end, seems short sighted to me.

Considering many cars on the lots have the noise it's only a matter of time until more people look for a solution as they sell more cars.

 

[victor_2019]

no car is perfect. if most people don't complain, why would hyundai spend the money to fix it?

Most people might not even hear this noise since it's at a high frequency and people's hearing deteriorates as they age (It's a well known fact that younger people can hear higher frequencies than older people).
Or they might hear it and not be bothered enough by it to complain. I only noticed this noise after specifically looking for it (after I read about it on this forum), and my girlfriend only heard it once I specifically showed it to her, and she's the one driving the car most of the time. She agreed the noise was somewhat annoying, but she hasn't said anything about it since, and she usually drives without AC and with the windows open. Who knows when, or if, we might have noticed it if I didn't visit these forums. How many other people drive the kona and won't notice this noise until you go and point it to them?

 

[MGrognon]

Who knows when, or if, we might have noticed it if I didn't visit these forums. How many other people drive the kona and won't notice this noise until you go and point it to them?

To be fair, I only speak French and English and I've found a total of at least 4 different forums (here, SpeakEV, AVEQ (French Canadian) and another one that I cannot seem to recall/find ; will update when I do) and 2 Facebook groups (Hyundai Kona Electric (EV) #HyundaiKonaEV and Hyundai Kona Electric-Québec) where some people have complained about this. So no ; it won't bother a majority of people, but it's not like a complaint specific to this forum either. I'm pretty sure if I spoke Korean or other languages I would find equivalent posts on forums in other languages too.

Will be looking forward to hearing feedback from Brennan (hopefully soon?).

 

[victor_2019]

can you point me to those other forum posts? I speak french too.

Whenever I tried to search for this, I found other people discussing other noise issues, but it was never this particular problem. "engine noise" is very generic and I can't seem to find any relevant discussions.

 

[MGrognon]

can you point me to those other forum posts? I speak french too.

Whenever I tried to search for this, I found other people discussing other noise issues, but it was never this particular problem. "engine noise" is very generic and I can't seem to find any relevant discussions.

The SpeakEV one has been linked in this thread already : https://www.speakev.com/threads/electric-motor-high-pitch-noise.137048/
AVEQ : http://forums.aveq.ca/viewtopic.php?f=58&t=106817
Facebook group (French) : here https://www.facebook.com/groups/HyundaiKonaElectricQuebec/permalink/2351019258550046/ (you need to be part of the group obviously, but there are multiple threads in that specific group where this is discussed, a lot of it is people not knowing what they're talking about and mixing up with VESS indeed, but there's at least 10+ people who complained about this. The easiest way is to search for "sillement" (hissing) in the group)
Facebook group (English - Actually SeanH from this thread) : https://www.facebook.com/groups/176622586290649/permalink/386230635329842/ (same comment as above)

 

[Brennan Raposo]

a reduction gear swap will not change a hissing that is caused by harmonic current vibrations in the motor.


People in this thread can't even seem to all agree on the noise, and some are mixing in other mechanical noise complaints because it comes from somewhere under the hood.

And Brennan Raposo might be describing something else entirely because he claims the sound is getting worse with the age of the car, with temperature (none of which would change if it's the harmonic hiss) and when he listened to the MP3 recording of the hiss, he said that's not the sound, his sounds worse. so he might as well have an actual mechanical problem.

Someone (I'm sorry, I can't remember who) posted something from a UK Hyundai Kona EV forum.
They posted audio clips of the identical noise to what I'm facing. A hissing noise. They went through the motions with their dealer and went through a reduction gear assembly swap - exactly as what is being recommended from my dealer. According to that user, the issue has been resolved. Whether that's permanent or not, who knows. But I'll wait and see what it does to mine!

 

[Brennan Raposo]

Hi Everyone,
I apologize for the lack of update - work's been killing me.
No REAL news yet. I got a call from my dealer, Burlington Hyundai, and they mentioned that they have a delivery date for my part(s) - Sept 6th. So I assume I will be booked in for an appointment in/around that date.

If anything else comes up I'll keep you all up to date!

 

[victor_2019]

Someone (I'm sorry, I can't remember who) posted something from a UK Hyundai Kona EV forum.
They posted audio clips of the identical noise to what I'm facing. A hissing noise. They went through the motions with their dealer and went through a reduction gear assembly swap - exactly as what is being recommended from my dealer. According to that user, the issue has been resolved. Whether that's permanent or not, who knows. But I'll wait and see what it does to mine!

it would be useful to have a good sound recording of the sound before and after the gear change, then we could tell exactly what the results are. Are you able to record it?

 

[victor_2019]

The SpeakEV one has been linked in this thread already : https://www.speakev.com/threads/electric-motor-high-pitch-noise.137048/

that is a very interesting thread.

but what is even more interesting is people reporting the same thing on other cars such as nissan leaf, the ampera (not sure if this is the Ampera, which is the chevrolet volt, or the ampera-e which is the chevrolet Bolt), the Kia soul, Ioniq etc.
So for the people asking why other cars don't make this sound ... they are.

 

[MGrognon]

that is a very interesting thread.

but what is even more interesting is people reporting the same thing on other cars such as nissan leaf, the ampera (not sure if this is the Ampera, which is the chevrolet volt, or the ampera-e which is the chevrolet Bolt), the Kia soul, Ioniq etc.
So for the people asking why other cars don't make this sound ... they are.

All I can tell you is I sat in : A Leaf, A Bolt, 3 Konas and a Model 3. It is likely true they all do SOME sound along the lines of what the Kona does, but the problem we can agree on is that on the Kona, the sound is one a very agressive "hiss" compared to others, and 2 way too loud/poorly isolated. And what we are still trying to figure out is whether some Konas have it way worse than others for some reason.

The Model 3 was as far as I can tell 100% exempt from ANY sound whatsoever (or very well insulated) compared to the other 3. The Leaf does have a high-pitched TONE (as in, I could probably identify which note(s) it emits on a music scale) but you cannot hear it in the car the moment you start moving. You hear it outside only if going very slowly (< 15 km/h or so), at least for the one I sat in / listened to. The Bolt has a similar "hiss" to the Kona but that you can barely hear outside the car, and cannot hear in it as far as I could tell but I was only in one for a very short amount of time. The Kona doesn't even compare.

Here's a (again poor quality) video of a guy driving a Bolt, Leaf and Kona to compare the sound. Again, poor audio but you'll likely hear what I mean.

 

[victor_2019]

that is indeed a poor quality video. I mostly just hear the VESS on the kona and wind noise. on headphones I can't hear much from the bolt (when I turn the headphones up a lot I can hear it) but I can definitely hear it on the leaf. to me in this video the leaf seems as loud as the kona if not louder. it's probably a different frequency which I can hear better.

I listened to the leaf and kona portions many times and on the leaf I can hear different noises: wind noise just like in the kona video, the "jet engine whine" of the electric motor/gear and I can definitely hear a high frequency hiss during acceleration, different from the jet engine whine.
on the bolt I mostly only hear the jet engine whine and lots of wind noise.
on the kona portion I can hardly hear the hiss. so if I were to base my opinion just on this video, I'd say the leaf is worse than the kona. I have one colleague with a leaf, I'm curious to see what it sounds like in real life. When I test drove a 40kwh leaf I didn't notice any such noises (but I hadn't noticed them when I test drove the kona either, so that's not saying much)

the guy says at the end that all three make this sound, it's just more present on the kona (he says at the end "more present/intense. not a lot, but still").


regarding insulation, I can't say much about the Chevy Bolt quality. When I was looking for an EV I sat inside a bolt and it seemed very cheap to me. so I can't believe it's got more insulation than a kona. but the kona definitively doesn't have a lot of sound insulation.

 

[electriceddy]

Hi Everyone,
I apologize for the lack of update - work's been killing me.
No REAL news yet. I got a call from my dealer, Burlington Hyundai, and they mentioned that they have a delivery date for my part(s) - Sept 6th. So I assume I will be booked in for an appointment in/around that date.

If anything else comes up I'll keep you all up to date!

Hopefully this will speed up the process of replacement parts:
https://insideevs.com/news/367499/hyundai-mobis-ev-parts-plant-2021/

 

[Brennan Raposo]

Hey All,
So after quite a lengthy delay, I finally had my car into the shop and it's back now.
unfortunately, the lower gear assembly DID NOT resolve the hiss. I feel bad for the dealer. They had my car in for 72 hours, they had to drop the entire battery and motor assemble to install the new lower gear drive. After all that work there is no noticeable change to the pitch/volume of the hiss. It's still very much noticeable.

I'm not sure how the lower gear assembly solved the hiss in that Kona in the UK. The sound they posted was absolutely identical to mine.
Unfortunately, the dealer believes it's just a poor engineering decision and there's not much more they can do until it's officially acknowledged by Hyundai. I honestly can't blame them at all. At this point - I essentially have a brand new car and am in the same position.

So it's Hyundai's move! If the 2020 model solves this issue. I will go to the better business bureau or get a lawyer involved to have my car replaced with a new one.